This mid-infrared image of the W3A star cluster in the inset was captured by the FORCAST camera on the SOFIA flying observatory in 2011. It is overlaid on a near-infrared image of the W3 star-forming region from the Spitzer space telescope. The SOFIA image scale is 150 x 100 arcseconds, and the red, green and blue colors represent 37, 20 and 7 μm. The red, green and blue colors in the background image from Spitzer represent 7.9, 4.5, 3.6 μm. SOFIA image: NASA / DLR / USRA / DSI / FORCAST team Spitzer image: NASA / Caltech - JPL.